Stunted maxima?

[Potsy]

I have a crocea and a maxima in my 75 gallon under 2x250watt 10k hqi. Both were purchased about 5 years ago at the same time and size (~ 3 inches). The crocea has since reached full size at 6 - 7 inches while the maxima hasn't grown the slightest bit. I can't imagine that it's a food issue or the crocea wouldn't have grown. What's wrong with my maxima?

 

[mbbuna]

how about a full tank shot showing where they are located in the tank

 

[Potsy]

I've re-aquascaped my tank so the visual wouldn't provide any real insight. They were both directly under each lamp at roughly the same height.